Wild claim: air travel emitted CO2 affects climate, El Niño

Oy! If there was ever a poster child for “correlation does not equal causation” this is it.

I have no doubt that when we have ENSO events, there are increased winds, resulting in faster flights, but to claim this extends to global scale AGW, especially since they are only using one region of flight path, is preposterous. I wonder if the correlation will hold if they look at say, New York to London, D.C. to London, and Miami to London? And further, what about the albedo effect of contrails from jet exhaust, wouldn’t that count as a negative feedback due to increased solar radiation reflection, possibly negating any GHG forcing contribution? See the photo below.

Jet contrails as seen by satellite. Credit NASA Langley Research Center

This paper from this grad student Hannah Barkley is the worst kind of science (just reading her bio sounds like she’s already made up her mind, science be damned), where oceanography students see themselves as meteorologists, and then extend that to seeing themselves climatologists, without looking at the entire picture of what effects jet travel has on the atmosphere.

Air travel and climate: A potential new feedback?

From Woods Hole Oceanographic Institution

Global air travel contributes around 3.5 percent of the greenhouse gas emissions behind/driving anthropogenic climate change, according to the International Panel on Climate Change (IPCC). But what impact does a warming planet have on air travel and how might that, in turn, affect the rate of warming itself?

A new study by researchers at the Woods Hole Oceanographic Institution and University of Wisconsin Madison found a connection between climate and airline flight times, suggesting a feedback loop could exist between the carbon emissions of airplanes and our changing climate. The study was published in this week’s Nature Climate Change.

“Upper level wind circulation patterns are the major factor in influencing flight times,” says lead author Kris Karnauskas, an associate scientist in WHOI’s Geology and Geophysics Department. “Longer flight times mean increased fuel consumption by airliners. The consequent additional input of CO2 into the atmosphere can feed back and amplify emerging changes in atmospheric circulation.”

The study began when co-author Hannah Barkley, a doctoral student in the MIT-WHOI Joint Program in Oceanography, asked Karnauskas a deceptively simple question. Barkley had noticed a direct flight she took from Honolulu back to the east coast–a route she has flown many times as field scientist–took far less time than expected, and she asked Karnauskas why that might be.

“The first thing that came to mind was, what did the flight-level winds look like that day,” Karnauskas says.

They quickly queried a database of the winds on a NOAA website, selecting for the altitude jets fly at and plugging in the date of Barkley’s flight, and saw that the jet stream that day was extra fast.

“There was just a big swath of extra-fast westerly winds stretching from Honolulu, Hawaii, to Newark,” says Karnauskas. “It was just serendipitous, as if she was part of some kind of golden mileage club where the atmosphere just opens up for you.”

The finding piqued their curiosity about just how unusual Barkley’s experience was, and the simple question led to a study of decades worth of data on flights between Honolulu and the North American West Coast (Los Angeles, San Francisco, and Seattle) by four different air carriers.

Through a database maintained by the Department of Transportation they were able to download departure and arrival data by each airline and the routes traveled–for every single flight that has occurred over the past 20 years. Because the upper level winds blow from west to east, the eastbound leg of a roundtrip flight is generally faster than the westbound leg. After quality controlling the data, Karnauskas plotted the differences in flight times for eastbound and westbound flights and noticed that regardless of the airline carrier, the difference for all the carriers looked the same, over the past 20 years.

Overview map and flight-time variability. a, Airline routes between HNL and LAX, SFO and SEA International Airports superimposed on the annual mean 300-mb zonal wind field (NCEP/NCAR Reanalysis, 1995–2013). The zonal wind field is contoured every 2.5 m s−1. b, Time series of ΔT

“Whatever was causing these flights to change their duration, was the exact same thing, and it wasn’t part of the airline’s decision-making process,” Karnauskas says. The hypothesis was born that climate variability (not just day-to-day weather) determines flight times.

He began digging into massive volumes of atmospheric data to assemble a “composite” snapshot of what the atmosphere looks like on days where the difference in flight times is large, versus small. When he overlaid the plots of the airlines’s differences in flight times with graphs of wind variability at climatic time scales, Karnauskas says he “was pretty blown away.” The plots were virtually identical.

Even after smoothing out the seasonal differences (the jet stream is always a little stronger in winter and weaker in summer), leaving him with the year-to-year variability, the match held up almost perfectly. Flight-level wind speed explained 91 percent of the year-to-year variance. The result also pointed toward the influence of El Niño – Southern Oscillation (ENSO) – a phenomenon Karnauskas has studied extensively.

As the temperature of the equatorial Pacific Ocean rises and falls, like a pebble in a pond, atmospheric waves are set off toward the higher latitudes of both hemispheres, where they change circulation patterns.

“I came into this study, thinking this is going to be a weird junket that is totally unrelated to anything I do, but it really led me back to El Niño, which is what I do.”

Karnauskas found that just by looking at the state of the tropical Pacific Ocean, he could predict what the airlines’ ΔT had been. For this so-called hindcast, “we’re talking about anomalies happening down at the equator that are affecting the atmosphere in such a spatially broad way, that it’s probably influencing flights all around the world.”

Their analysis also determined that the difference in flight times between eastbound and westbound flights on any given route didn’t cancel each other out; rather there was a residual. In other words, when an eastbound flight became 10 minutes shorter, the corresponding westbound flight became 11 minutes longer.

According to Karnauskas, it took some “obsessive drilling into the data to find that residual, and at face value it seems very minor.” The net additional flying time for a pair of eastbound and westbound flights between, for example, Honolulu and LA is only a couple minutes for every 10 mph speedup of the prevailing wind. But, he says, “the wind really fluctuates by about 40 mph, so multiply those couple of minutes by each flight per day, by each carrier, by each route, and that residual adds up quickly. We’re talking millions of dollars in changes in fuel costs.”

Once the researchers had proven that the atmospheric circulation affects how long planes are in the air, they began to wonder about the impact climate change would have on the airline industry.

According to the study, there are approximately 30,000 commercial flights per day in the U.S. If the total round-trip flying time changed by one minute, commercial jets would be in the air approximately 300,000 hours longer per year. This translates to approximately 1 billion additional gallons of jet fuel, which is approximately $3 billion in fuel cost, and 10 billion kilograms of CO2 emitted, per year.

“We already know that as you add CO2 to the atmosphere and the global mean temperature rises, the wind circulation changes as well–and in less obvious ways,” says Karnauskas.

Based on what they had learned about the airlines’ residual flight times, the researchers explored how climate models predict the atmospheric circulation to change and to make some estimates of how much more CO2 will be emitted by the airline industry in the face of those changes. Currently, global climate models to not incorporate inputs from air travel, so this potential feedback is missing from our state-of-the art models.

Karnauskas believes this information could be useful for the airline industry to more efficiently plan for future fuel costs, reallocate fuel resources, refine the predicted flight durations for their customers, and better manage all the inconveniences and manpower related to flight delays.

While this study focuses on a very small subset of the total global airline traffic, Karnauskas has plans to expand this study to include all US and European flights – a massive undertaking. To work with such large datasets, Karnauskas has been granted access to Azure, a powerful cluster of networked computers operated by Microsoft, under a special research grant jointly offered between Microsoft Research and the White House Climate Data Initiative.

In reflecting on the findings of this project and the simple question Barkley had initially asked, Karnauskas says one of the biggest surprises is that the airline industry doesn’t seem to be aware of the flight time patterns.

“The airline industry keeps a close eye on the day-to-day weather patterns, but they don’t seem to be concerned with cycles occurring over a year or longer,” he says. “They never say, ‘Dear customer, there’s an El Niño brewing, so we’ve lengthened your estimated flight duration by 30 minutes.’ I’ve never seen that.”

###

As is typical with many of these shonky papers, they don’t provide a link to it in the press release, lest anyone read it for themselves and see how ridiculous the press release claim is. So I sought it out myself.

The airline industry closely monitors the midlatitude jet stream for short-term planning of flight paths and arrival times. In addition to passenger safety and on-time metrics, this is due to the acute sensitivity of airline profits to fuel cost. US carriers spent US$47 billion on jet fuel in 2011, compared with a total industry operating revenue of US$192 billion. Beyond the timescale of synoptic weather, the El Niño/Southern Oscillation (ENSO), Arctic Oscillation (AO) and other modes of variability modulate the strength and position of the Aleutian low and Pacific high on interannual timescales, which influence the tendency of the exit region of the midlatitude Pacific jet stream to extend, retract and meander poleward and equatorward1, 2, 3. The impact of global aviation on climate change has been studied for decades owing to the radiative forcing of emitted greenhouse gases, contrails and other effects4, 5. The impact of climate variability on air travel, however, has only recently come into focus, primarily in terms of turbulence6, 7. Shifting attention to flight durations, here we show that 88% of the interannual variance in domestic flight times between Hawaii and the continental US is explained by a linear combination of ENSO and the AO. Further, we extend our analysis to CMIP5 model projections to explore potential feedbacks between anthropogenic climate change and air travel.

I took a flight from Philadelphia to L.A. in the 60’s that arrived 45 minutes early. At the time, it was a passenger flight record. We were told the jet stream was slow that day, and the pilot decided to take advantage of it, pedal-to-the-metal all the way.

Yes, of course the air lines would spot a cycle a mile off – if it were important. The air lines certainly know the value of day-to-day wind information. I flew from Singapore to Auckland once, and our pilot came on saying that he would not go directly to Auckland but planned to make a detour round Ceduna in South Australia to take advantage of a faster wind there – to save 20 minutes or so! I found it so exhilarating that our pilot was sitting there eyeing the wind patterns just like skippers of the sailing ships of old. Was Barkley re-inventing the wheel? Or exactly what was the import of her research?

Nearly every time I get into an airplane, part of the Captain’s welcoming message includes the influence of the current winds on our ETA. I am sure that the first time the Wright Brothers were able to follow a course upwind and then downwind, they noticed a difference in the duration. These “researchers” spent a bundle of bucks to “discover” something that everyone connected with aviation probably either knows or suspects.

Funny you should mention the Wright Brothers, of course the Wright Brothers knew about the difference in airspeed and groundspeed long before their first flight, (they were not stupid), but the Wrights made a fundamental mistake when they choose Kitty Hawk. They wanted to make their flight somewhere that usually had about 15 mph winds. They found out that Kitty Hawk had average winds of about 15 mph.
The fundamental mistake that they made is the same one that many climate alarmists still make these days. They forgot that average winds of 15 mph could mean that one day the winds are 30 mph and the next day zero mph. They suffered through many days with too little wind, and many days with too much wind. Climate alarmist today still seem not to be able to understand what an average temperature means.

It took a college student to discover east bound flights travel faster than west bound flights? Anyone who has flown as much as once a year knows the jet stream travels from west to east and is the reason why east bound flights can often make up time and arive ahead of schedule while those travelinging the opposite diection fight head winds and seldom arrive early. 40 years of such travel taughtme that Boston to Dublin takes 5 hours while the return takes 6. Nice to know our student recognized what all of us have known for decades. Unfortunately, it doesn’t say much for her education that she makes such a leap to climate change.

I apologize to Kris Karnauskas, the sun, moon, and stars and anyone and anything else, but I can’t help myself after trying to pronounce Kris’ name in my head.
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Karnauskas; isn’t that what people from Brooklyn call themselves when they move to Nebraska?
.
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Can’t say how it’s really pronounced, but that’s how I make it out to be.

What Hannah Barkley didn’t figure is that eastbound flights will fly at altitudes and routes that maximize the effect while westbound flights operate at altitudes and routes that minimize the effect. And on occasion, operators will throttle back a little when eastbound to save even more fuel.

The east-west routes across the North Atlantic consist of a series of one-way parallel “tracks,” as we call them, made up of sequential points of latitude and longitude. Flights along the same track are sequenced by time, one behind the other. Or, they are stacked vertically, with a minimum of 1,000 feet between each plane.

[ … ]

The tracks go west-to-east in the evening, when the vast majority of planes depart North America for Europe, and east-to-west in the mornings and afternoons, when most flights are headed the other way. [ … ] The locations of the tracks are different every day, varying with weather and winds aloft. Track “A” on Tuesday might consist of a totally different string of latitude/longitude fixes than Wednesday’s track “A.”

You hit on a lot of it. Something that popped into my head was that they say in cars we waste more fuel going 65 mph than 55 mph, so even thugh it takes us longer to get somewhere at 55 mph we used less fuel than speedy Gonzalez going 80 mph. So how an airplane takes it’s route avoiding the strongest head winds is probably more important for fuel consumption than how long the plane was in the air.

Jared
Quite: The author/researcher makes an assumption that the amount of time in the air directly equates to fuel burn. As you point out an economic cruise will take longer and this applies to all planes with the exception of Concorde. So statements like the following are meaningless:
“…commercial jets would be in the air approximately 300,000 hours longer per year. This translates to approximately 1 billion additional gallons of jet fuel, which is approximately $3 billion in fuel cost, and 10 billion kilograms of CO2 emitted, per year.”

Where are the “trend” lines? We know that jet streams are affected by the large eddies such as the Aleutian Low and the heat gradient from the equator to the poles. But the tiny little graphs in the article provided look pretty flat and meaningless.

Oh wait. They are going to put things into a model. THEN we’ll get trends!!!

“Further, we extend our analysis to CMIP5 model projections to explore potential feedbacks between anthropogenic climate change and air travel.”

Has any warmist ever acknowledged a NEGATIVE feedback to CO2 warming??
Empirical measurements suggest there are some, since there’s been no recent warming correlated to the steady rise in CO2. (18.5 years)

I don’t understand the beef with this paper. Stronger winds affect flight time. If airlines understood the effects of El Nino on upper-level winds, they could produce more accurate arrival times. That’s what the paper seems to be saying. Very interesting work.

The title of this post implies something completely different from what is contained in the paper.

“I don’t understand the beef with this paper. Stronger winds affect flight time. If airlines understood the effects of El Nino on upper-level winds, they could produce more accurate arrival times. That’s what the paper seems to be saying. Very interesting work.”

No it wasn’t. The point was to finger how anthropogenic CO2 will wreck air travel unless a committee is formed to reduce fuel inefficiencies and what not, plus to suggest the need for a lot more money to research this dastardly wicked problem that the airlines no nothing about. sarc off

Come on Steven, you are intelligent enough to see a crap paper not worth a dissertation.

Pilots do throttle back with a big tailwind. Saves gas, and no sense arriving too early and sitting on the ramp waiting for a gate that’s still occupied.

On a headwind-tailwind round trip, the greater the wind, the greater the total trip time. (That was the principle underlying the Michelson-Morley experiment, which led to the theory of relativity.)

Companies have been fine-pencilling wind effects since forever. How much attention is paid to fuel burn over other considerations depends on fuel price. Other factors are seasonal weather patterns and hourly running cost of the aircraft, which includes maintenance scheduled by total flight hours. It all goes into the mix along with a heavy dose of past experience for the green eyeshade people to balance, and that’s where you get the scheduled flight times that the pilots try to meet.

Sorry, kind of, about that “Nope” reply Mosh, But I thought you would like stupid one word responses,since you are so good at them.
Thinking that an understanding of El Nino on upper level winds could help airlines make better flight plans is so stupid it isn’t even wrong. It is just plain stupid.
Every day pilots get winds aloft forecasts these forecasts are confirmed or disproven by pilots who have flown the same or similar routes earlier. The forecasts are updated hourly. It matter not if the change in wind speed or direction is due to El Nino,The Polar vortex, or God Sneezing. The reports by pilots will either verify the forecast or not.

Steve M, what part of
“Once the researchers had proven that the atmospheric circulation affects how long planes are in the air, they began to wonder about the impact climate change would have on the airline industry.

According to the study, there are approximately 30,000 commercial flights per day in the U.S. If the total round-trip flying time changed by one minute, commercial jets would be in the air approximately 300,000 hours longer per year. This translates to approximately 1 billion additional gallons of jet fuel, which is approximately $3 billion in fuel cost, and 10 billion kilograms of CO2 emitted, per year.”
====================================================
did you fail to read?

David A July 13, 2015 at 8:01 pm
“Once the researchers had proven that the atmospheric circulation affects how long planes are in the air, they began to wonder about the impact climate change would have on the airline industry.

….. 300,000 hours longer per year. This translates to approximately 1 billion additional gallons of jet fuel, which is approximately $3 billion in fuel cost, and 10 billion kilograms of CO2 emitted, per year.”

No it doesn’t. You cannot make a direct correlation between flight time and fuel burn. This is just lazy thinking and built on an assumption that someone studying the climate can teach fuel burn to someone who flies planes for a living. Making the fuel last is uppermost in a pilots mind and depending on conditions flying slower will burn less fuel so the above assumption is valueless.

The idea of learning something from existing data, of looking at flight times as a kind of wind map was good. The flight time from A to B and then B to A, is the result of many things true but can contain wind information. What wasn’t mentioned is crosswind conditions at altitude would result in something between the two extremes. That is meridional winds, wavy jet stream. These kinds of ideas used by the paper is what should be pursued.

I think it unfair to blame Hannah Barkley for this waste of journal space. She is neither the lead author not the corresponding author. If anyone deserves the brunt of your scorn, it is Kris Karnauskas, followed by the other two co-authors (both of whom are likely senior to Barkley), not to mention the journal editor and reviewers. Even if Barkley thought “this is silly”, to say so would have taken more nerve and confidence than most grad students can muster.

This is not new. We know the general state of the ENSO affects the global atmospheric angular momentum (the drag on Earth’s rotation caused by the winds, in other words the strength of the winds) and even the length of an average Earth day.

During an El Nino, the winds slow down (the east-to-west Trade Winds in the tropics slow down and the west-to-east mid-latitude and high latitude winds slow down).

Its actually a small impact. The Earth day gets milliseconds longer in an El Nino

Right now Global Atmospheric Angular Momentum has increased sharply as a result of the El Nino. (Relative GLAAM over the last year).

I’ve wondered how much recent warming might be explained this way. The timing of increased air travel correlates pretty well with rising temperatures, so I suspect one could rig an empirical study to “find” a strong effect, but is there a good basis to infer how strong the effect actually is?

So, is it reasonable to be a general (lukewarmer) CAGW skeptic but still see a substantial warming effect from rising air traffic?

I definitely picked the wrong career. I wish I’d known I could make a handy living writing up papers about attaining a partial ignorance from my previous total ignorance regarding things well known by everyone else.

I would like to know what data were used to determine flight times. Airline schedules / flight results, as far as I know, are based/published on gate to gate times, and not wheels up to touchdown. So… flying to LAX from Phoenix will take longer than it “should” not only due to prevailing westerly winds, but also because of increased taxiing time at LAX (and more air traffic at LAX as well.) I don’t know – maybe this all cancels out, but until we know what data was used, it’s impossible to determine validity of the study.

“Karnauskas has been granted access to Azure, a powerful cluster of networked computers operated by Microsoft, under a special research grant jointly offered between Microsoft Research and the White House Climate Data Initiative.”

Oh I see: we’ll have volumes and volumes of data that are meaningless…

Part of the results are highly plausible — that ENSO and AO together explain 88% of inter-annual variation in the average difference in flight times east-west vs. west-east. Well, duh. That’s simply to say that these two factors explain most of the inter-annual variation in the jet stream’s path and speed, at least between Hawaii and the U.S. west coast.

The paper’s claims for the importance of its results, however, are highly implausible — that annual fuel costs of $47 billion could vary by $3 billion depending on the state of ENSO etc., when total flight times clearly do not vary by anywhere near the same proportion. Moreover, fuel usage is less than proportional to flight times, as flight times only effect the lower amount of fuel needed to maintain airspeed and altitude, not the fixed amount of fuel needed to raise the airplane to altitude. Short-haul flights involve proportionately more of the latter sort of fuel usage.

I’m not clear what assumptions or claims the paper makes about how global-level climate change affects the jet stream’s path and speed. I gather that that is held out as an issue for future research, while the present paper focuses on the effects of ENSO and AO.

“The impact of climate variability on air travel, however, has only recently come into focus, primarily in terms of turbulence . Shifting attention to flight durations, here we show that 88% of the interannual variance in domestic flight times between Hawaii and the continental US is explained by a linear combination of ENSO and the AO. ”

So they study the influence of natural variability on flight times.

problems?

Then they ask the question.. what if it gets warmer..and will that effect airlines

pretty fricking basic.

Many businesses now are looking at what a warmer future may mean to their business.

[And as you are fond of pointing out, one data point is not the world, i.e. Honolulu. If they were doing real science, they’d test some other routes for the posited CO2 connection. But they didn’t, and instead interpolated their opinion:
“we’re talking about anomalies happening down at the equator that are affecting the atmosphere in such a spatially broad way, that it’s probably influencing flights all around the world.”

No issues with the wind speed and El Nino, as you say, pretty fricking basic, CO2/AGW causation, not so much. -Anthony]

“Many businesses now are looking at what a warmer future may mean to their business.”.
Since we are talking about changes of less than 0.1 C per decade, most of these companies are not going to be in business by the time this makes any appreciable difference- how many companies that were around 100 years ago are still in business?
The planes that are in use now (many of them over 20 years old) will be replaced with more modern planes. New planes, such as the Gulfstream G650 have a much higher maximum altitude – 51,000 ft. Compare this to older planes that fly at 39,000ft. Planes equipped with winglets can fly at 42,000 ft – usually about the jet stream.

What the heck is the matter with you Mosh? Anyone who has even a slight knowledge of aerodynamics knows what effect warmer weather has on airlines. I have more than a slight knowledge of aerodynamics having a BS in aeronautics. But this stuff is so simple and so basic I don’t understand why it is being talked about at all, the airlines fully understand it, and a grad student’s paper is of no use to them at all. That is what we complaining about, what make this paper publishable ? it is so elementary as to be useless.

Tom – You mean like someone who has to ask someone this question. –“Barkley had noticed a direct flight she took from Honolulu back to the east coast–a route she has flown many times as field scientist–took far less time than expected, and she asked Karnauskas why that might be.” ???

Might wonder why they do not know the definition of Climate – generally taken as the average over 30 years. Now let’s apply 20 years worth of data to check it out.

“No issues with the wind speed and El Nino, as you say, pretty fricking basic, CO2/AGW causation, not so much. -Anthony]”

causation of what?

1. you already admit that C02 will cause warming.
2. The question is how much.

basically you have never disputed the causation, you just dispute the amount of warming.
Since the science isnt settled it could be high or it could be low.

It is totally reasonable to explore the problem space. That is, it is totally reasonable and rational to explore the presumed effect under the assumption that the warming is small or medium or high.

We do this type of analysis all the time

We dont know, for example, how tax cuts will specifically impact the deficit going forward.
We have models. We use them all the time.
you dont know how, for example, your retirement portfolio will play out, but its totally reasonble and rational to look at a variety of scenarios.

So, there is nothing wrong with assuming causation, you yourself accept it. We see in the lab that c02 increases plant growth. In the lab of the world we see the same thing— sometimes.
We see in the lab that C02 restricts cooling via radiation.. In the lab of the world we see the same thing.

So, its not the causation you object to, its the level of warming. But the level of warming is uncertain.
Its not settled last time I looked. So its reasonable and rational to look at a variety of possible futures.

[Lead sentence: “Global air travel contributes around 3.5 percent of the greenhouse gas emissions behind/driving anthropogenic climate change, according to the International Panel on Climate Change (IPCC)”, implying it air travel affects itself. You can’t attribute causation of the specific emissions from Jet planes to driving ENSO and winds. And, they didn’t test the theory to see if it holds up elsewhere. That’s my issue. And please don’t try to lecture me about things I already know. Lately, you’ve adopted a “holier than thou” attitude, much like some people we know. – Anthony]

“… commercial jets would be in the air approximately 300,000 hours longer per year. This translates to approximately 1 billion additional gallons of jet fuel, which is approximately $3 billion in fuel cost, …”

Wow! Commercial jets actually get the equivalent of 6 mpg! Four of us should buy one (from an IPCC delegate) and carpool – er, jetpool – to work. We’d actually save on gas.

Ok, they’re a little off on that one. But, that’s ok; even if a commercial jet doesn’t get 6 mpg we’d save on fuel anyway because they’re way off on the price of fuel too. The spot price for jet fuel hasn’t exceeded about $1.80 per gallon since December 2014. Last time I checked $3.00 and $1.80 are not the same thing. (But give it time.)

Oh, well. These numbers are good enough for climate work. And, also for Obama’s White House Climate Data Initiative. And people wonder why the economy’s still in the doldrums 6 years in?

Oh!!! Up near the stratosphere there are very stong winds. Imagine that? Guess we found that out in WW2 when the B-29 folks almost ground to a halt with 150+ mph head winds up there above 25,000 feet. And the Empire at that time was exploiting that phenom to send fire ballooons to the U.S. Sheesh, that was 70 years ago.

Where do these folks get “vetted” before checking into all the “science” about stuff like weather, atmosphere and stuff like that? Guess it’s all “peer” review, and the peers are just as clueless.

With the methods used in the paper or ones like them one could conclude the data supported one of these two regimes:
With data that is older, we could learn about past wind patterns. This paper reminds me of the Jennifer Francis work on zonal NH wind flows.

What an idiotic piece of junk research. This self-important genius seems to think the airlines, flight schools, and private pilots are somehow missing the boat on considering jet streams, wind patterns, and weather when flying from here to there. I would love to be a fly on the wall in the backroom where pilots gather. They wouldn’t use this (Cough! Hack! Gag!) dissertation in an outhouse.

Trouble is the WH Climate Data Initiative provided the funding for this silliness and ‘they’ will use this kind of stuff to set regulations. It’s the same thinking that’s behind setting fuel economy standards for over the road trucks: As if the Owner Operators and trucking companies have no self interest in maximizing their own fuel economy. Society is to be governed by professors and their graduate students – god help us.

As a professional pilot for many years, I can assure you that all of us still standing are extremely familiar with all kindsa “weather” and atmospheric phenom and stuff like mountain waves amd rotors on downwind side of mountains and………

I can see it now when at the bar.

Gums, ” Hey, some climate dweeb has just now discovered the jet stream.”

Spectre, ” No kidding?”

“Yeah, seems like they also found out about contrails, too. They might even reflect the sun rays back into space and cut back on “global warming” a bit.”

“Wow, imagine that?”

Gums sends….

P.S. I am losing track of the decimal points but if we humans are only cranking out 4% of the annual Co2, and the jets are only cranking out 3.5 % of the 4%, then what;s the big deal? I would imagine that bovine farts and termites contribute more that that, ya think?

My dearly departed mother considered becoming a professional pilot (fat chance back then) and took at least one University level aerodynamics class. I have her class notes. Incomprehensible to me but fascinating nonetheless.

Pamela Gray July 13, 2015 at 2:55 pm
The trouble is there is a tendency not to refer to those in the doing professions about what they think or to provide advice. There was a court case in the UK about an airfield’s operations and the aviation expert acting for the airfield was barred from giving evidence because as an expert he was considered biased.

Pamela Gray July 13, 2015 at 5:42 pm
Not sure if it is of interest but please look up Barbara Harmer and her interesting background.

All that work for nothing. When teleportation technology comes on line, right after wind turbines replace coal, gas, hydro, and nuclear power plants, we won’t give a rat’s patootie about which way the wind blows.

I guess they didn’t factor in the actual number of flights in any given year, nor the increasing efficiency of jets or any other factors, nor any other variable, except flight times. What kindergarten nonsense. I can not believe that this passes for “science”.

If they wanted to do some real science based on Meteorology 101, they could have studied the effect of the weaker jet streams from the warming of the higher latitudes. When we warmed in the 1980’s/90’s, the warming was focused in the higher latitudes. Jet streams are a result of the meridional temperature gradient. Weaken that and you weaken the jet stream.

Don’t just pick one route and make this climate change connection based on something that might effect that region…………from El Nino’s and apply it everywhere.

There’s an entire planet, much of which has weaker jet streams from the beneficial warming of the higher latitudes. What about the rest of the planet and flights?

What a sad, sad circumstance this whole CAGW is in seducing kids into this cult of conformity so that they are trained to prepare such utter drivel basically for the publicity and self justification of their department or organisation. It has sweet F.A. to do with science.

Pamala friend. Please think FAA. All of this is moot. No one will sanction a fuel load based on the “hope” of a tail wind. Nor arrival times based on the wind.
This is a classic example of poor mentoring. Hannah Barkley should have been redirected to some “experts” at one of the airports to learn how things work and why things work.
But then it is the blind leading the blind.
Pamala, you mentioned your late Mother. Earlier this year I was cleaning out my late mother’s house. I found my Dad’s pilots license. He was blind in one eye.. As am eye, pun intended. It was an eye opener to me; no pun this time
I know I’m opening up Pandora’s box but oh well.
michael

Most of my trips via air have been coast to coast. Arrival times take into account the conditions of the jet stream present when you board. Your advanced ticket will say one thing. When you get on the plane the pilot says another thing.

Bingo.
Its up to the pilot and the air traffic controller.
But then if these people get their paws on the FAA I don’t see myself traveling by air.
Oh and I have traveled to Europe several times. As a student and just for fun.
michael

I flew the “lites”, but the “heavy” folks actually changed their course to exploit the jet stream over the Pacific.

So one day I faced about a hundred + knot head wind and got worried about gas. Requested the wind at FL400 and dude says light and variable. So trop was just a thousand feet above me and I was cleared to FL400 and sure enough – no wind!

Exactly. Aircraft performance depends on air density. That is why El Niño/La Niña appear in the figure from the paper – they alter the temperature profile of the atmosphere. Less dense air, airplanes go faster (assuming they are not limited by engine performance).

On average, over many flights, an airplane flying westbound will take off directly towards its destination and land straight ahead into the westerly prevailing wind at its destination. An airplane flying eastbound will take off into the westerly prevailing wind and fly many miles turning though 180° to head towards its destination. On arrival in the vicinity of the destination it will fly many miles past the airport and turn through 180° to approach the airport into the prevailing westerly wind.

On average, therefore, eastbound flights will fly many more miles on the same route as a westbound flight because of the requirement to land into wind which on planet earth prevails from the west.

This whole analysis is utterly meaningless because of the uncertainty in measuring flight durations. There is at least three different ways to define flight times, none of which is actually relevant in this case. There is “off blocks/on blocks”, from take off power on until leaving the active runway after landing and from (nose) gear expansion until (nose) gear compression. The last is the one usually recorded by onboartd recording systems. However for this kind of analysis to be meaningful, time spent in holding patterns should be deducted, and also corrections applied because a pilot will often depart from an optimum flight profile in order to conform to a “slot” time at a busy destination airport.

Just a guess but the engine power outputs may vary somewhat dependent upon air density which itself is also dependent on temperature in addition to altitude. However the turbine airflow characteristics may be able to compensate to prevent power loss at higher altitudes; in which case the reduced air density at high altitudes may afford less wind resistance which would then improve performance.

Jet aircraft performance improves dramatically with altitude. Colder air improves engine efficiency, thinner air decreases drag. This effect is so strong that the optimum profile for short flights is actually climbing half-way and let down at flight idle the other half.

Hi Billy
E.M.P. (sorry just being evil) Take your pick. ANYTHING that will shutdown a airport or air corridor. Take your pick. Last year my son and I were delayed by over 24 hours due to great lake effect lightning. Its not just aircraft in the air.
Okay you did say “altitude” Stacking aircraft. Or just plain “can’t get there from here!”
again take your pick.
michael
michael

Good effort digging out the data, but it might be nothing more than pilots who live on the mainland want to get home sooner, so they put on a little extra speed, the way engineers on military ships add a few extra shaft rpm when heading home. We called them “liberty turns and they were seldom, if ever, noticed by the deck officer, at least officially. Sounds like it’s not been noticed by those in charge of the airlines…until now. Which means it was effective.

If the primary author is correct in her recollection regarding Hannah, I consider Hannah’s question rather lacking in basic atmospheric science acumen for a graduate student involved in Woods Hole. I think she should be properly chastised as should her professors.

Pam found the paper. They used Wheels Up to Wheels Down for their times.

I have a hunch that may introduce some of the variation they refer to in their notes but the key issue is what they say about the use of the models:“Analyzing the predicted response of 300-mb zonal winds to increased radiative forcing
105 by 34 GCMs included in the Coupled Model Intercomparison Project, Phase 5 (CMIP5) 10 paints
106 an uncertain future.”

In other words, the models don’t provide a clue.

As for the notes:
“i Bureau of Transportation Statistics, Research and Innovative Technology Administration, U.S.
Department of Transportation.
ii MIT Global Airline Industry Program, Airline Data Project
(http://web.mit.edu/airlinedata/www/Revenue&Related.html).
15
iii The BTS statistic “AirTime” is used, which is wheels up to wheels down.
iv The sensitivity of westbound flight durations to u300 is greater than that of eastbound flights of
the same route, so an increase in u300 lengthens the westbound flight by slightly more than it
shortens the eastbound flight resulting in a net increase in total flying time (“T). The average
sensitivity of “T to u300 for the flights analyzed is 0.38 minutes flying time per m s-1 zonal wind.
v Bureau of Transportation Statistics, Research and Innovative Technology Administration, U.S.
Department of Transportation.
vi National Air Traffic Controllers Association.
vii Assume burn rate 1 gal per second. Varies depending on aircraft and many other variables.
viii Assume emissions coefficient 9.6 kg CO2 per gal (eia.gov/environment/emissions/co2_vol_mass.cfm”

Good Golly Miss Molly, have most of us lost our minds here? It matters not a wit to the airlines what the average global temperature is, or will be, nor does it matter to them what the average winds are globally, and only slightly matters to them what the averages are on a given route. What concerns them most is what is the actual temperature on the day, the hour, and second they are flying a route, and what are the winds on that route as it is being flown. In other words climate really doesn’t matter much to airlines, and global climate doesn’t matter at all. Weather matters a great deal, but climate not so much. However, to the small extent that climate matters, it would be nice if the people making the climate models would try, for a change, to make them accurate, airlines would have lost a lot of money if they put stock in climate models over the last 18 years.

A pilot or the airline and/or ATC will decide the route and altitude at the time or bit before. An El Nino operates on longer time scales. It might be possible to tease out information on how much jet fuel to have on hand in Hawaii for the next 6 months. Using medium time scale conditions to put energy resources in the correct place for the demand has been done by others. Fuel in no small issue. It weighs a lot. You want a nice reserve over the ocean but that comes at a cost. Some of the additional fuel goes into carrying itself. I think the novelty here is using the flight time data and trying to say something about wind patterns and speeds. We need more monitoring and this paper suggests ways to have that with existing data sets. Flight route, MSP to Anchorage to Tokyo. Carrier, Northwest. Plane, 747. What could flight times from the past tell us?
We might say we knew what the jet stream was doing in the past and planned accordingly. What if we look at it again in a new way?

Complicating things but interesting, one opinion is:
“In practice, the speed at which a plane is flown is determined by balancing the desire to make the trip as quickly as possible with the desire to make the trip as inexpensive as possible. In practice, the minimum fuel consumption airspeed (for the assigned flight level) will usually be chosen, unless that would make the flight arrive late, in which case the airspeed that gets the flight there on time is chosen, at the cost of fuel economy.” http://www.quora.com/In-an-airplane-do-you-travel-more-distance-in-the-same-amount-of-time-the-higher-up-you-fly
You’re on the plane. It’s at altitude. Where to set the throttles? What’s 20 extra minutes if it saves a lot of money and builds the fuel reserve? Seem the highest mpg value is chosen a lot of the time, without government interference as far as I know. What may be of interest is how do you fly faster? Bigger engines or fly where there’s less drag? At 30,000 feet the air pressure is only 30% of sea level pressure. That’s a lot less air molecules slowing you down. So you make engines that can fly there. Not bigger ones to fly lower with.

Flights are planned using 1 day forecast winds aloft, which are fairly accurate given the short time frame and the lack of complications well above the surface. Longer range forecasts aren’t much use, unless you’re dealing with hurricane tracks and such.

The flight plans are usually minimum cost, not minimum fuel. Cost balances the fuel burn rate with the fixed and operating costs of the aircraft. Fly more slowly to save fuel, you spend more time in the air, and maintenance costs are based on aircraft hours flown. Routes and altitudes are chosen for economy and comfort (turbulence). Fuel loads and reserves are set by FAA regs and company operating policies. Each aircraft type has its own preferred range of altitudes and speed.

Computers figure it all out, and leave room for pilot adjustments and contingencies.

Not quite so much these days. A lot of the most expensive items are now cycle-based. And engine maintenance (most expensive of all) is largely based on thermal cycling and thermal fatigue, which mitigates against using high engine power.

By the way I can easily come up with another feedback going the other way. During long overwater flights airlines tend to fly cruise-climb profiles. I. e. the altitude is slowly increased as the fuel is burned off and aircraft weight decreases, since on the whole fuel burn per mile decreases monotonically with altitude. On such flights a part of the time will normally be spent flying above the tropopause, conventionally set at FL 360. This proportion will increase with longer flight times.
Now there is an oddity with the effect of Greenhouse Gases, they have a cooling effect in the Stratosphere above the Tropopause. This is because the stratosphere is not heated from below like the troposphere, but instead by the direct absorption of incoming solar UV, while this absorbed heat can only be lost as LWIR radiation by GHG, most of which escapes into space. So by flying longer in the stratosphere aircraft will actually cool the Earth.

Oh yes, I’m quite aware that this effect is absurdly small, but so is the effect claimed in this paper.

If air travel is the cause of such things then why do they have these international conferences and fly in thousands of people every few years? Now that they know this (or think they do) will they stop flying around the world for every little whim? Nope!

I was married to a commercial pilot and before joining QANTAS he flew high altitude spy planes with an altitude of 65,000 ft. The Vulcan V bombers afterwards. Nothing you can do to combat Jet Streams. But amazingly other pilots on his training for 707 (mainly Canadian or South African who hadn’t four jet experience) didn’t know the affect of Jet Streams on air craft movements. Because they hadn’t flown as high possibly. Anyway it’s snowin’ in Armidale only light so far, but an American taxi driver told me that in Seattle they got snow too. So what are they bitchin’ about again! It’s like vapour trails they think it’s pollution or government trying poison people. It’s almost medieval thinking when people didn’t know anything about weather or strange happenings.

Commercial air craft companies do take note of weather conditions and temperatures. Commercial aircraft avoid thunder storms obviously. Down Drafts, icing are one of the major reasons for aircraft disasters. They fly high and there the temps are often minus or always minus. Haven’t you ever seen Air Craft disasters on TV – Frightening. Although a lot can be put down to pilot error, some are not and blamed on strange weather events. And we still haven’t found MH370.